I keep going through bearings

[WishIhadatruck]

Here is the quick story with my 2001 Grand Prix.

*Early spring 2008, hit a HUGE pothole (twice). Growling noise 2 weeks later.

*Late spring 2008, mechanic replaces driver side front wheel bearing (Napa part). All is quiet.

*Late spring 2009, more growling noise. It gets worse, I go back to the mechanic. I've also got popping noises when turning sharp as I back out of my garage. They replace my lower ball joints (getting some play), replace my struts and strut mounts (popping sound), and replace both bearings in the front (drivers side under warranty).

*2 days later, it seems like all is good but around 65-70mph I still hear a growling noise. They replace the driver's side bearing again. It is like a new car again.

*Jan 2010, bad growling noise. Around Feb 1 my mechanic replaces both front wheel bearings again, both under warranty.

*In Feb or March it seems like I can hear bearing noise again but my tires are so noisy I can't tell for sure. Late March I remove my 9 year old Blizzaks and put on brand new Goodyear Assurance Fuel Max tires. Tire noise is gone but I hear bearing noise around 55-65mph. If I swerve right it disappears but under certain right sweeping turns it also gets lounder. Maybe both are bad again?

Why do they keep going bad? Are the replacements just junk or is there something else with my car that can be causing them to go bad? I'm tempted to buy some ACDelco bearings and install them myself, I'm pretty sure I can handle the job. The only thing holding me back is wondering if there is another problem I don't know about that could cause my bearings to go bad so quickly. I'd hate to install new ACDelco ones just to have them go bad as well.

 

[Kestas]

Time to change mechanics. Even aftermarket bearings aren't that bad. The number one reason for bearing failure is improper installation. We've found that some mechanics air-impact the hub nuts on. That is a no-no that can result in premature failure. They need to be properly installed wth a torque wrench.

Or your problem is being misdiagnosed and the problem is elsewhere and not the bearings. CV joints?

 

[WishIhadatruck]

They said they checked out the CV joints and the axle shafts last year and found nothing wrong. It is perfectly quiet for a period of time after they do the work so I think the bearings have always been the cause of the noise.

Should I try to replace them myself? If so should I use ACDelco or another brand?

 

[d00df00d]

Maybe the hubs are bad, causing the bearings to wear out prematurely?

 

[Quest]

Originally Posted By: Kestas
Time to change mechanics. Even aftermarket bearings aren't that bad. The number one reason for bearing failure is improper installation. We've found that some mechanics air-impact the hub nuts on. That is a no-no that can result in premature failure. They need to be properly installed wth a torque wrench.

Or your problem is being misdiagnosed and the problem is elsewhere and not the bearings. CV joints?

If wheel bearings are the issue, and assuming that quality bearings are being installed repeatedly, then the problem lies on your mechanic's end and not the materials itself.

wheel bearings has to be properly pre-loaded and installed according to specific instructions based on the type of bearings itself. If the mechanic cannot do this the "correct" way more than once then he is basically "done for" on my list and I will never go back to him from that point onwards.

**Kestas is right that no impact-gunning, bearings have to be properly loaded/pre-loaded before the car is lowered onto the floor, etc. Many rigid steps to follow in order to install bearings properly to ensure reliable, long service life.

Q.

 

[scurvy]

Improper installation is the #1 killer of replacement wheel bearings, but a confounding factor is drivetrain wear. Refresh all the mounts & bushings to be sure those aren't exacerbating the issue.

Personally I like SKF, F-A-G or Timken bearings.

Funny story, when I replaced a front wheel bearing in my Golf, I went to my FLIAPS to get a replacement as I forgot to put in the circlip before pushing the hub through. Guy behind the counter brought out two boxes: one was marked 'wheel bearing' in a terrible 1970s design, the other was a Canadian-made SKF. He handed them both to me and said, 'we've got a discount bearing for $28 and OEM for $43.' Just for S&G, I opened up the Chinese-made 'discount' wheel bearing box and took a look at the actual bearing. While I was inspecting it, one of the inner races and grease seal fell out of the bearing onto the counter.

The parts guy never flinched as I picked it up, put it back together and back in the box and stated my intentions to only buy the OEM bearing. While ringing my order up, he laughed and said, 'We never sell any of these discount bearings if people actually look at them, but so many people only buy on price alone.'

 

[eljefino]

Have read about needing just a little toe-in in your alignment to load the bearings driving down the street. Maybe the ball joints changed the alignment and shot that bearing.

Otherwise it's not too suprising, larger V6 FWD GMs eat bearings as a way of life. They are pretty easy to change yourself, usually undoing struts and tie rod ends give you enough space and you don't have to pop lower ball joints.

 

[bmod305]

Couple of thoughts:

Napa does carry two different grades of hub assemplies. Top grade are made by SKF and the value line are sourced from China. Most of the SKF hubs are made in the USA, Korea, or Mexico. They are all made in SKF plants.

In our five store group, we do take some units back under warrany. The funny thing is that there are about 3 garages that warranty more hub units than the other ones put together. After checking with the garages, they all had the same issue-they used an air impact to tighten the hub nut and none of them properly torqued the nut on to the correct specs. They just tightened it up until the impact wouldn't turn anymore. It should be tightened and torqued by hand. Most garages are trying to beat the flat rate and blame their supplier when something comes back. My guess is your garage is using an impact gun or something else is wrong with the drivetrain/suspension.

FYI on AC Delco. It is a common misconception that AC Delco parts are the same ones that GM uses to build their cars. That is no longer the truth; they were spun off years ago from GM. AC Delco is just a marketing name; they no longer manfacture any parts. They out source them and rebox. If you want an OE hub, you will have to buy an actual GM part from a GM dealer. Don't buy the AC Delco unit from the dealer; you need the "long part number" GM hub.

Dave

 

[Kestas]

Originally Posted By: d00df00d
Maybe the hubs are bad, causing the bearings to wear out prematurely?

This is a hub unit. The hub is replaced with the bearings.

 

[WishIhadatruck]

Thanks for all the input. My guess is they are using the cheaper Napa part. I was looking this morning at the Napa website and noticed they had 2 models of bearing with a significant cost difference.

As far as AC Delco parts, it was Delphi that was spun off back in the late 90's. It is correct AC Delco is just a name, but the name is owned by GM. Are you sure bmod305 that AC Delco parts aren't GM parts? Maybe I'll check out the better Napa bearings in person at a Napa store or the Timken bearings at Autozone.

I'm familiar with older bearings like those in the front of my RWD wagon which are like those on trailers. Are the FWD hub/bearing assemblies preloaded by the axle nut? Is that what they are over tightening (possibly)? Or is the bearing preloaded within in the hub before it is installed? I have the factory manuals so I'll check into the torque requirements.

 

[mechtech2]

Pontiac has had lots of wheel bearing problems.
Grand Ams were almost common in the shop for this.
Too heavy cars on tiny bearings.
Yours seem to be the world record, though.
I also suspect improper installation.

 

[WishIhadatruck]

Originally Posted By: mechtech2
Pontiac has had lots of wheel bearing problems.
Grand Ams were almost common in the shop for this.
Too heavy cars on tiny bearings.
Yours seem to be the world record, though.
I also suspect improper installation.


I was already suspecting an installation issue, you guys have nearly confirmed it for me. My '94 Grand Prix went 212k miles for me with the original bearings, this is driving me nuts.

 

[bmod305]

Delphi and AC Delco are not the same. Delphi is huge supplier to most of the car manufacturers including GM. A Delphi part is an OE part while AC Delco isn't. Delphi makes parts while AC Delco makes boxes for someone elses parts.

Napa does offer many Delphi parts i.e. ign parts & fuel pumps. They do not buy the entire Delphi product line.

Dave

 

[WishIhadatruck]

Originally Posted By: bmod305
Delphi and AC Delco are not the same. Delphi is huge supplier to most of the car manufacturers including GM. A Delphi part is an OE part while AC Delco isn't. Delphi makes parts while AC Delco makes boxes for someone elses parts.

Napa does offer many Delphi parts i.e. ign parts & fuel pumps. They do not buy the entire Delphi product line.

Dave


I'm aware they are seperate. I worked for GM, then Delphi, and then we got spun off (always at the same plant). I now work in another industry and won't go back. Delphi makes some of the GM parts and AC Delco parts but not always. For instance, back when my Grand Prix was made the 3.8L in my car received Delphi fuel injectors. The supercharged 3.8 used Bosch injectors. If I went to the dealer back then to buy injectors they would both come in a GM or AC Delco box but would come from 2 different suppliers (Delphi or Bosch). I bought AC Delco iridium spark plugs made by NGK a couple of years ago but that doesn't mean that GM plugs wouldn't have been NGK iridium plugs as well.

If you go to GM.com they will direct you to AC Delco to lookup parts for your car. My guess is AC Delco is the same as GM (although sometimes they offer multiple options such as performance rotors) where as Delphi may have originally made the OEM parts but not always anymore as they have dowsized dramatically (especially US manufacturing). I'm sure AC Delco (the name) is owned by GM, why wouldn't they sell GM parts? I'm not sure, maybe they would but I can't see why.

Maybe the important thing to do when I shop for bearings is to make sure they look good and don't say "Made in China"?

 

[pbm]

I put a Timkin in my Buick Century 2 years ago and have had no problems since. The OE bearing wasn't making noise but the wire to the ABS broke right at the bearing which caused the ABS light to come on. I couldn't solder it so I put a new bearing in. I torqued it as per the instructions (118 lbs. I think) and have had no problems.

PS: The design of the ABS wire is pretty poor...it should have a little plug so that it can be changed without replacing the entire bearing.

 

[labman]

Originally Posted By: mechtech2
Pontiac has had lots of wheel bearing problems.
Grand Ams were almost common in the shop for this.
Too heavy cars on tiny bearings.
Yours seem to be the world record, though.
I also suspect improper installation.


I had a lot of problems with my 92. I blamed part of it to cheap replacements form AAP.

 

[Kestas]

The country of origin for both OEM and aftermarket is all over the place. Our company makes excellent OEM bearings in Mexico and questionable aftermarket bearings in the US. The deciding factor should be "to what quality are they manufactured?".

OEM has stringent standards, and our feet are held to the fire by the automaker's warranty program. Aftermarket bearings have no feedback system beyond the typical 12-month guarantee that most mechanics and supply houses give.

 

[willix]

Over tightening distorts the inside bearing race causing the bearings to ride the edges of the race quickly wearing in unevenly as the bearing material contaminates the lubricant.

 

[WishIhadatruck]

Well, I replaced both front wheel bearings with AC Delco units. It the GM part# right on the box as well. Made in the USA.

So far so good, nice and quite again. Do you think the axle nut was on too tight if I had to use a 5 foot bar to break it loose?

 

[SteveSRT8]

Maybe just a little too tight?

Both the preparation and the installation of wheel bearings in a tapered spindle is an art form.

Do it right they last 200K plus. Do it wrong and you may not make it around the block!